public class Example3_6{
   public static void main (String args[]){
     double sum =0,item = 1;
     int i=1,n = 20;
     while(i<n){
          sum=sum+item;
          i=i+1;
          item= item*(1.0/i);
     }
     System.out.println("sum="+sum);
   }
}
